Combined effects of Pt nanoparticles and oxygen vacancies to promote photothermal catalytic degradation of toluene

Pt/Mn-TiO2 photothermal catalysts with abundant oxygen vacancies are prepared by loading Pt onto a composite of MnOx and TiO2 using MIL-125 as precursor (abbreviated as Mn-TiO2) and subsequent hydrogen reduction treatment. Under light irradiation with intensity of 625 mW/cm2, the optimal 0.65Pt/Mn-TiO2 catalyst can achieve toluene conversion of 90.4 % and CO2 yield of 85.6 %, respectively, and maintain stable activity for at least 30 h in the presence of coke and water. The introduction of Pt nanoparticles improves the utilization of solar spectrum and facilitates the generation of more oxygen vacancies. The comparative experiments of photothermal catalysis and thermal catalysis further verify that light not only acts as a heat source but also enhances catalytic reaction through photocatalysis and photoactivation of lattice oxygen. In the follow-up work, catalytic oxidation under natural sunlight is performed on 0.65Pt/Mn-TiO2 to reach 75.0 % of toluene conversion, displaying a good practical application potential.